so I added the heater yesterday night and have a thermometer in the water too. The reading on the thermometer was about 70 deg Fer. Today morning the reading is still the same. The box said I should wait 24 full hours minimum to have the water reach required temp.
Also I have put the heater at the bottom because that is the only falt surface there is the sides are rounded....am just so afraid the betta will touch the heater and get burned or something.
lastly emeraldmaster, i didn't understand what you meant about the heater sitting at the top